The Mocona falls are a spectacular sight, that would be quite touristy if it wasnt for the nearby Igauz Falls. The Ro Uruguay drops no more than 20 meters at this place, but the falls are as wide as three kilometers as the falls are diagonal on the already wide river.
For the moment there is no infrastructure on the Argentine side of the river to get close to the falls. Hence getting to the viewpoint in the middle of the river implies wading through the shallow river water. Its refreshing and not dangerous, but it is a little tyring.
On the Argentine side the place can be visited from El Soberbio (cheap good value place to stay right next to the bus terminal, ask in the closest bar) or other nearby towns. From El Soberbio you can arrange a day trip with four wheel drive (50 to 100 peso per person). Construction of a good road is in progress, so within a couple of years there should be buses up to the site. Although there is hardly any traffic, you might get lucky and get a ride from other tourists going to Mocona. At 5 kilometers from the falls there is a place to stay for those who want to have more time to explore the falls and the surrounding wonderful jungle.
In the wet season (December to February) the falls may disapear under the rising water levels.